This invention relates to a sensor and an associated algorithm and tools to detect when a person has fallen. More specifically, the invention relates to evaluating sensor data with respect to characteristics of the fall to accurately determine when the fall has taken place.
The proliferation of motion and other types of sensors enables new applications that take advantage of data gathered from the sensors. It is known that when people are old or ill the aspect of falling can be dangerous. A lot of times, these people are alone, and once they have fallen they are in need of assistance but do not have the ability to obtain the assistance. At the same time it is important to differentiate between a fall and a fall-like event. Without such differentiation, the sensor will yield a significant quantity of false—positive data, which may unnecessarily burden emergency response personnel.
Many industry fall detection solutions detect Low G (“weightlessness”) as an indicator that a body is being pulled down by gravity. It is very appealing because the pull can be detected just as a change of a motion vector magnitude, so the device can be in any orientation towards gravity. However, as we realized collecting test data, Low G is also present in many normal everyday life activities. Virtually any energetic action may contain Low G periods. It is seen in walking, sitting, missing a step, even rising up. Low G can also be masked by rotations that happen in falls. There is an important benefit from not using the Low G: the requirement for accelerometer resolution can be substantially reduced.
All falls occur for one reason: loss of support which in turn can be a result of going out of balance or structural collapse of the support. Both can happen for many reasons. In an accident a person can be pushed out of balance. In a normal life somebody can just exceed their ability to keep the balance while going through standard everyday routings, trips, or slips. Elderly people are balance-challenged for age related reasons. Regardless of the basis for the fall, there is a need to accurately determine when a fall has occurred so that assistance can be provided when necessary.